Tamper evident closures with tear handles are well known in the prior art. Generally, prior embodiments of these closures have included a tear handle to be grasped by the consumer and pulled such that a frangible portion of the closure wall is broken allowing an annular portion of the closure wall to be removed, thus permitting the consumer to remove the reclosable upper portion of the closure from the bottle. The removable portion of the closure wall is defined by an annular line of weakness and a vertical line of weakness to allow this portion to be easily removed from the remaining re-closable upper portion of the closure. Prior closures of this type may be seen in U.S. Pats. No. 4,066,182, 4,687,114, and 4,801,032. It is common for the lower portion of the closure tear strip to come into contact with a downwardly sloped portion of the bottle neck finish, and for the lower portion of the tear strip and the corresponding portion of the bottle neck finish to be forced together at a relatively high pressure during the bottle capping process; this may result in rupture of the vertical line of weakness during capping. It is also common for these closures to be produced such that the fit between the lower portion of the closure and the bottle neck finish is loose enough to prevent the vertical line of weakness from being ruptured during capping. However, this loose fit also may create a gap between the lower portion of the closure and the bottle neck finish which could facilitate tampering.
Closures have been detailed in the prior art which use other means to eliminate this gap and improve tamper resistance as seen in U.S. Pats. No. 4,190,175, 5,027,969, and 5,307,948. These designs place a removable barrier on the bottle which prevents access to the lower region of the closure. This eliminates the need for a tight fit between the closure and the bottle. However, it is difficult to reproduce these features on a typical blow molded bottle with the accuracy and low cost that are possible on a standard injection molded or compression molded closure.
The present invention provides a novel tear handle which prevents damage to the vertical line of weakness in the removable portion of the closure wall when large forces are applied to the top surface of the closure during capping. The tear handle has a weak region which is designed to deform under pressure and shield the vertical line of weakness from high forces which can cause the vertical line of weakness to fracture. Shielding the vertical line of weakness from excessive capping forces allows the closure to be designed to fit the bottle more closely. This improved fit between the closure and bottle improves the tamper resistance of the closure as it is installed on the bottle.
There has therefore been a desire to have an improved bottle closure with an improved tamper evident tear strip which does not fracture during the capping operation, which provides for a better, tighter fit between bottle and closure, and which is easier for the consumer to tear from the container than tear strips in the prior art.